Arcuate slide out drive assembly for enclosure

ABSTRACT

A drive assembly utilized in combination with slide out includes a beam attached to a beam guide in an arcuate support rail that is attached to the slide out. The beam may have a first row of teeth and a second row of teeth thereon, where the first row of teeth and the second row of teeth extend parallel to each other on opposite sides of the beam. In addition, the teeth in the first row of teeth are offset relative to the teeth in the second row of teeth. The drive assembly further includes a drive gear having a first gear wheel that engages the first row of teeth and a second gear wheel that engages the second row of teeth, as well as an actuator coupled to the beam to selectively extend and retract the beam. The beam may deflect with respect to the arcuate support rail based on its location and the location of the beam guide to aid in leveling of the slide out.

This application is a continuation-in-part of U.S. application Ser. No.15/809,496, filed Nov. 10, 2017, which is a continuation of U.S.application Ser. No. 15/222,490, filed Jul. 28, 2016, which claims thebenefit of U.S. Provisional Application No. 62/199,753, filed Jul. 31,2015, which are hereby incorporated by reference.

TECHNICAL FIELD

This disclosure relates to a slide out drive assembly for reconfiguringan enclosure and, more particularly, to an enclosure having at least oneslide out that may be extended to alter the configuration of theenclosure and/or provide more room within the enclosure. Mostparticularly, the present disclosure relates to a drive assembly havinga rack and pinion drive used to extend or retract the slide out.

BACKGROUND OF THE INVENTION

Expandable enclosures are often used in connection with recreationalvehicles or trailers that have portions that extend and retract to allowthe enclosure to be transported in a compact configuration and extendedto a more spacious configuration when stationary. To that end, theserecreational vehicles and trailers are provided with slide outsincluding slideable rooms and other structures that increase orreconfigure the usable space. Existing slideable rooms and other slideouts may be time consuming to install and their operating mechanisms mayinclude components that add a great deal of weight and complexity to theenclosure. Since most enclosures having slide outs are used inapplications where they need to be transported, it is desirable toreduce the weight of the enclosure as practically as possible. Likewise,reducing the complexity of the slide out drive assembly is desirable interms of the labor needed to install the drive assembly and operation ofthe drive assembly by the user.

SUMMARY OF THE INVENTION

In some embodiments of the present disclosure, a drive assembly forreciprocating a slide out disposed in an opening of an enclosure betweenan extended position and a retracted position is disclosed. In someembodiments, the drive assembly includes a support rail defining achannel, the support rail being arcuately shaped; a beam having a frontportion that is attachable to the slide out and having a guide portionopposite from the front portion that is at least partially enclosedwithin the channel; and an actuator coupled to the beam to selectivelyextend and retract the beam relative to the support rail, wherein acurvature of the support rail varies orientation of the slide outrelative to the opening based on the position of the guide portionwithin the channel. In some examples, as the beam is extended throughthe support rail, the curvature of the support rail angles the beamdownwards such that the guide portion of the beam is oriented higherthan the front portion of the beam. In some examples, as the beam isretracted through the support rail, the curvature of the support railangles the beam upwards such that the guide portion of the beam isoriented lower than the front portion of the beam. In some examples, thesupport rail includes a symmetrical or asymmetrical arcuate shape. Insome examples, the drive assembly further includes a drive gearengageable with the at least one row of teeth provided on the beam, andin some of these examples, the support rail is configured to press thebeam into engagement with the drive gear. In some examples, the guideportion includes a slide member configured to slide within the channeland, in some of these examples, the slide member is configured to rotaterelative to the beam. In some examples, the actuator is selected fromthe group consisting of an electric cylinder, a hydraulic actuator, anda pneumatic actuator.

In some examples, the drive assembly further includes a drive gearengageable with the at least one row of teeth provided on the beam. Inthese examples, the at least one row of teeth provided on the beam mayinclude a first row of teeth and a second row of teeth, and wherein thedrive gear includes a first gear wheel engageable with the first row ofteeth and a second gear wheel engageable with the second row of teeth.In some of these examples, teeth in the first row of teeth are offsetrelative to teeth in the second row of teeth, and wherein the first gearwheel is rotationally offset relative to the second gear wheel. In someof these examples, the support rail is configured to maintain engagementof the first and second row of teeth on the beam on the first and secondgear wheels of the drive gear.

In some examples, the drive assembly further includes a drive gearconnected to the support rail, and the drive gear includes a first andsecond gear wheel that are engageable with a first and second row ofteeth provided on the beam, wherein the first and second gear wheels aremounted on a common hub. In some of these examples, the drive gear mayfurther comprise a support wheel mounted on the common hub, the supportwheel being configured to rotate independently of the common hub andengaging the beam between the first row of teeth and the second row ofteeth. In some of these examples, the drive assembly further includes astub shaft axially extending from and rigidly attached to the commonhub, wherein rotation of the stub shaft imparts rotation on the firstgear wheel and the second gear wheel to thereby drive the beam; and across member that couples the stub shaft to a second drive assembly, thecross member synchronizing the drive assembly and the second driveassembly.

In some embodiments of the present disclosure, an expandable enclosureis disclosed. The expandable enclosure may include an enclosure havingan opening, a slide out provided in the opening of the enclosure, andextendable from the enclosure; and a drive assembly for extending andretracting the slide out. In some examples, the drive assembly includesa support rail defining a channel, the support rail being arcuatelyshaped; a beam having a front portion that is attachable to the slideout and having a guide portion opposite from the front portion that isat least partially enclosed within the channel; and an actuator coupledto the beam to selectively extend and retract the beam relative to thesupport rail, wherein a curvature of the support rail varies orientationof the slide out relative to the opening based on the position of theguide portion within the channel. In some examples, the enclosure is aself-powered or towable vehicle. In some examples, the actuator isselected from the group consisting of an electric cylinder, a hydraulicactuator, and a pneumatic actuator.

In some examples, the drive assembly further includes a drive gearconnected to the support rail, wherein the drive gear comprises a hub; afirst and second gear wheel arranged on the hub and respectivelyengaging a first and second row of teeth provided on the beam; a supportwheel arranged on the hub and engaging the beam between the first row ofteeth and the second row of teeth, the support wheel being configured torotate independently of the hub; and a stub shaft axially extending fromand rigidly attached to the hub, wherein rotation of the stub shaftimparts rotation on the first gear wheel and the second gear wheel tothereby drive the beam. In some of these examples, across member isprovided that couples the stub shaft to a second drive assembly, thecross member synchronizing the drive assembly and the second driveassembly.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective exterior view of a portion of an enclosurehaving a slide out according to the present invention, showing the slideout in an extended position;

FIGS. 2A and 2B is a side elevational view of a drive assembly in aretracted and extended positions, respectively;

FIG. 3 is a top perspective view of a drive assembly according to one ormore embodiments;

FIG. 4 is an enlarged bottom elevational view of a front portion of adrive assembly according to one or more embodiments;

FIG. 5 is an enlarged bottom elevational view showing a rear portion ofa drive assembly according to one or more embodiments;

FIG. 6 is a top perspective view of a drive assembly according toanother embodiment having two drive assemblies connected by across-member;

FIG. 7 is a top plan view of the drive assembly shown in FIG. 6 with thedrive assembly shown in an extended position in dashed lines;

FIG. 8 is a partially sectioned front elevational view of the driveassembly depicted in FIG. 4;

FIG. 9 is a side elevational view of a beam and arcuate support rail inaccordance with aspects herein;

FIGS. 10A to 10C are side profile views depicting various embodiments ofthe arcuate support rail;

FIG. 11 is a side exterior view of a portion of an enclosure having aslide out according to the present invention, showing the slide out in aretracted position; and

FIGS. 12A and 12B are front views of the drive assembly according to oneor more embodiments.

DETAILED DESCRIPTION OF THE INVENTION

An “enclosure” as used herein may include any partially or completelyenclosed space. The enclosure may be stationary or mobile. Mobileenclosures may be self-powered or towable, and include but are notlimited to mobile homes, recreational vehicles, and trailers. The term“expandable enclosure” refers to an enclosure that has the ability toalter its configuration and in some cases create more interior space.For example, an expandable enclosure may include one or more portionsthat extend and retract to selectively reconfigure the space defined bythe enclosure. These portions are often referred to as “slide outs” or“slideable rooms.” A slide out may include a portion that is movedrelative to the enclosure to change the configuration of the enclosureincluding but not limited to increasing the space available within theenclosure. Slide outs may be of various size and shape as required by agiven enclosure. Also, slide outs may expand and retract in any knownmanner including, but not limited to pivoting and telescoping relativeto the main portion of the enclosure. The example shown in theaccompanying drawings, therefore, should not be considered limiting.

FIG. 1 shows a portion of an enclosure 10 with a slide out 20 in anextended position. During movement or transport of the enclosure, theslide out 20 may be fully retracted to configure the enclosure 10 in acompact configuration. The enclosure has a wall 13 defining an opening12 that receives slide out 20. Positioned about the edges of the opening12 is a frame 14. Frame 14 may include side jambs 15, a header 17, and afooter 19. In the example shown, the jambs 15, header 17, and footer 19are linear and joined at right angles to define rectangular opening 12,but other arrangements can be provided in alternative embodiments. Theslide out 20 may be extended or retracted within frame 14 to alter theconfiguration of enclosure 10 as needed. Optionally, a seal, such as apolymer strip may be provided about the frame 14 to provide a weathertight seal between the frame 14 and the slide out 20. Slide out 20 maybe of any size or shape as required by a given application and may forma compartment, dinette, wardrobe, library, bedroom, closet, kitchen,etc.

Enclosure 10 may be a self powered vehicle, such as a recreationalvehicle, or may be towable, such as a trailer. The enclosure 10 may beone that is designed for living or temporary accommodation or maybe awork vehicle such as a mobile classroom, library, or temporary officespace. Alternatively, the enclosure 10 may be a stationary structureincluding but not limited to modular housing.

As shown in at least FIGS. 2-7, a drive assembly, generally indicated bythe number 50 may be mounted adjacent to the frame 14. In the exampleshown, drive assembly 50 is located on or below floor 22 of enclosure10. Drive assembly 50 may include a beam 52 that attaches to slide out20 or may form part of the frame of the slide out 20. In the exampleshown, an end bracket, generally indicated by the number 30, attaches toa cross member 32, which is attached to the floor 22 of slide out 20.Bracket 30 may have any shape or cross member 32 may attach directly tobeam 52. In the example shown, bracket 30 includes a face plate 34 thatattaches to beam 52 and to cross member 32 or slide out 20 at its topsection. To provide further support for slide out 20 in the extendedposition, bracket 30 may include a support 36 that extends downward tocontact a supporting surface. In the example shown, a telescopic supportextends downwardly from the end plate and has an end that may berotating to release and extend the support downwardly to contact thesupporting surface.

Beam 52 is moveable between a retracted position and an extendedposition to selectively extend and retract slide out 20. As best shownin FIG. 4, beam 52 includes a first row of teeth 54 and a second row ofteeth 56 that are formed on opposite sides of the beam 52. The first rowof teeth 54 and second row of teeth 56 extend parallel to each otherand, as shown, may be formed on respective flanges on either side of thebeam 52. Teeth 54, 56 may be formed in any known manner. For example,the rows of teeth 54, 56 may be stamped into beam 52. The beam 52 may bea monolithic member or be formed by multiple pieces.

According to one embodiment of the invention, beam 52 is formed by apair of c-shaped members having a vertical center section 66 andoutwardly extending bottom and top flanges 62, 64. These c-shapedmembers are joined at the center sections and form a central channel orgroove 68 where the sections are joined together. In the example shown,the rows of teeth are stamped into the bottom flange 62 of each c-shapemember such that the rows of teeth 54, 56 are located on either side ofthe groove 68.

While aspects herein, including beam 52, describe c-shaped members,channels, or other aspects, variants including solid structures can beutilized in alternative embodiments. For example, beam 52 may insteadformed by an I-shaped member or by a pair of u-shaped members. Further,different tooth arrangements, including a single row of teeth across oneor more members, can be employed without deviating from the scope orspirit of the innovation.

A drive gear assembly, generally indicated by the number 70, isconfigured to engage the first and second rows of teeth 54, 56. Drivegear assembly 70 may include a first gear wheel 71 and a second gearwheel 72 that both engage respective rows of teeth. The drive gearassembly 70 may further include a support wheel 44 that engages beam 52between the first and second rows of gear teeth 54, 56 to allow freemovement of beam 52 in the axial direction. A support wheel 44, firstgear wheel 71, and a second gear wheel 72 may all be mounted on a commonhub 74. Any support wheel may optionally be mounted on suitable bearingssuch that it rotates independently of hub 74. In one example, a supportwheel is fixed to hub 74 and rotates with first and second gear wheels71, 72.

Alternative drives can also be utilized. In another embodiment, a beltdrive 73 can be employed either to turn a drive gear assembly or othercomponents influencing the relative position of beam 52 or otherelements.

The first and second rows of teeth 54, 56 may be symmetrical about thecenter line of beam 52. Optionally, as shown in FIG. 4, the first row ofgear teeth 54 and second row of gear teeth 56 may be offset in the axialdirection with respect to each other as generally represented by numeral78. The offset 78 between first and second rows of teeth 54, 56 may beany amount. For example, the offset 78 exemplified in the figures is oneand a half teeth. This offset 78 ensures that at least one tooth on eachwheel is engaged at all times thereby helping to spread the load ofslide out 20. Likewise, the first gear wheel and second gear wheel 71,72 may be mounted in corresponding rotationally offset positions to matewith the offset first and second rows of gear teeth 54, 56. In this way,greater stability is provided by maintaining contact with more than onegear tooth on either side of the beam 52 at all times.

According to another aspect of the invention, a method of forming beam52 includes (i) stamping a first c-shaped member in a die, the firstc-shaped member having a first end and a second end; and (ii) stamping asecond c-shaped member in the same die, the second c-shaped memberhaving a first end and a second end. Each c-shaped member has a bottomflange and a row of teeth formed thereon. The teeth formed on the flangeeach correspond to a tooth on a gear wheel as discussed above. Thespacing of the cogs/teeth on gear wheels 71, 72 and on rows 54, 56 maybe set such that the cogs on gear wheels 71, 72 contact the teeth inrows 54, 56 in alternating fashion. An offset between rows 54, 56 may beprovided to time contact of the teeth in this alternating fashion.

The teeth in one row are offset with respect to the teeth in the secondrow. For example, the teeth in one row begin before the teeth in theopposite row and the teeth are spaced by an offset 78. According to oneaspect of the invention a method of forming the offset teeth in a singledie is provided. A single die is provided to mold or stamp one half ofbeam 52. The mold creates a first beam member 52 having a row of teeth54 that start a first distance from a first end of first beam member andterminate a second distance from the second end of the first beammember. The first and second distances are not equal and differ by theamount of the desired offset 78 between the rows of teeth. That way,when a second beam member is provided by the die, the second beam membermay be rotated and joined to the first beam member to create the secondrow of teeth 56 with the desired offset 78 between the first and secondrows of teeth 54, 56.

In the example shown, beam 52 can be constructed by a pair of c-shapedbeam members having rows of teeth 54, 56 formed as described above. Inparticular, the first c-shaped member having a first row of teeth 54 isprovided, and then a second c-shaped member is placed adjacent such thatits second end is adjacent to the first end of the first c-shapedmember. In other words, one of the c-shaped members is flipped aroundand placed back to back with the other c-shaped member. Once in thisconfiguration, the c-shaped members may be fastened or welded togetherto form beam 52. The fact that the rows of teeth 54, 56 each have atooth profile that corresponds to every other tooth on a gear wheel, andthe offset 78 between the rows of teeth causes alternating engagement ofthe teeth 54, 56 by corresponding gear wheels 71, 72. In other words, asthe first gear wheel 71 moves toward disengagement of a tooth in thefirst row of teeth 54, the second gear wheel 72 is beginning to engage atooth in the second row of teeth 56. In alternative embodiments, asdiscussed above, alternative structures distinct from a c-shaped membercan be employed.

In embodiments, stub shaft 80 may extend axially outward from hub 74 andis connected to hub 74 such that rotation of stub shaft 80 causes thefirst and second gear wheels 71, 72 to rotate and drive beam 52. Thestub shaft 80 may be manually rotated with an appropriate tool or drivenby a motor. As shown in FIG. 7, a motor may be coupled to stub shaft 80.A motor may be provided for each drive assembly, when using more thanone drive assembly or, as shown, stub shaft 80 may also be used to linkand synchronize multiple drive assemblies 50. There, a tandem driveassembly is shown having two drive assemblies 50 linked by a crossmember 90 that couples stub shafts 80 extending from each hub 74. Crossmember 90 may be any suitable coupler including but not limited to atelescoping square cross-sectioned tube as shown. In the example shown,tube is extended to fit over a stub shaft 80 on each drive assembly 50and pinned in place. In this example a single motor can drive both driveassemblies 50 via cross member 90.

By coupling drive assemblies 50, a pair of beams 52 may be used toextend and retract slide out 20 through a common actuator 100. Actuator100 may be a motor coupled to drive assembly 50 or an electric,hydraulic, or pneumatic cylinder that is coupled to a portion of driveassembly 50 to cause the beam 52 to extend and retract. In the exampleshown, in FIGS. 3 and 6, an electric cylinder 102 is used and has atelescoping rod 104 that attaches to an actuator bracket 106 that iscoupled to beam 52 through face plate 34. In the embodiment shown inFIG. 6, the actuator 100 drives a first beam 52, which in turn causesthe gear wheels 71, 72 to rotate on teeth 54, 56. Rotation of gearwheels 71, 72 rotates hub 74 and the stub shaft 80 attached thereto,which is coupled by cross member 90 to the hub 74 and stub shaft 80 ofthe opposite beam 52. Rotation of opposite hub 74, in turn, rotates gearwheels 71, 72 on that hub 74 to drive second beam 52 at the same timefirst beam 52 is driven by actuator 100. FIG. 6 depicts extension of thedrive assemblies 50 to move the slide out to an extended position asshown in FIG. 1. The extended position is shown in dashed lines in FIG.7, with the reference numerals indicated with a prime (′) marking. Inparticular, as shown, in the extended position, actuator 100 drivesbeams 52 outwardly along with the cross member 32 that attaches to theslide out 20 to the extended position 52′, 32′.

The drive assembly may be mounted beneath the body of the enclosure 10or within the sub frame of the enclosure 10. Other locations may be useddepending on the orientation of the drive assembly. In the exampleshown, a pair of substantially parallel support rails 150 are providedto house and support beams 52.

Each support rail 150 has an arcuate shape. As best depicted in FIGS. 2,9 and 10, each support rail 150 has a vertex 252 between first supportend 254 and second support end 256. As depicted in the Figs., thearcuate shape of support rail 150 is symmetrical. However, alternativesare contemplated herein, to include configuring vertex 252 differentdistances from first support end 254 and second support end 256.

In embodiments hereunder, each support rail 150 is level (to include,but not necessarily limited to, mounting each at the same height). Thecurvature of each support rail 150 angles beam 52 downward as it isdriven through support rail 150.

Because each beam 52 may not share the curvature of support rail 150,and for example may be straight, beam guide 258 can be attached to beam52 to retain coupling with support rail 150 where the geometry of beam52 does not accord with that of support rail 150. Beam guide 258 can beattached in a movable fashion to permit relative movement betweensupport rail 150 and beam 52 in two or more dimensions. In theembodiment depicted in at least FIG. 2, guide coupler 259 is arranged torotate about beam guide 258 but is fastened in a static manner to beam52. Here, beam guide 258 is a rolling element that matches the innergeometry of support rail 150; however, other embodiments of beam guide258 are also embraced hereunder, to include pieces which translatethrough arcuate support rail(s) 150 without rotation (e.g., sliding).

In use, beam 52 is permitted to displace vertically with respect to itsrespective support rail 150 without becoming dislodged or stuck throughinterface with the inside geometry of support rail 150 and theassociated beam guide 258. In this manner, as beam 52 extends, therebydeploying slide out 20, beam 52 and slide out 20 can both displace ortip opposite the direction of vertex 252 to permit leveling of slide out20 with respect to enclosure 10.

Earlier designs using a ram and support channel typically required areasonably loose tolerance between the ram and support channel, at timesup to one eighth of one inch or more. This tolerance can create noise,wear, or other problems, including seizing between the ram and channel,and/or displacement of the ram such that the teeth of the ram gearsbecame disengaged or slipped in relation to the teeth of the drivewheel. The disclosed arrangement using beam guide 258 permits reductionof these tolerances to eliminate the drawbacks of earlier drivesolutions.

Each support rail 150 can define a channel that receives beam 52 andsupports beam 52 as it extends and retracts. A stop 192 may be providedat a rear portion of a channel to adjust the length of the channel whenusing beams 52 of different lengths depending on the amount of extensionrequired for a given slide out 20. The stop 192 may also be used toalign beam 52 within the channel. In the example shown, stop 192includes a yoke 194 having a pair of forwardly extending arms 196defining a gap 198 there between in which the center portion 66 of beam52 is received. Stop 192 may include one or more cross bars 200 thatsupport arms 196 and extend across a channel. As shown, cross bars 200may be supported on rollers 204 received within each sidewall 154 of thesupport rail.

As discussed previously, drive assembly 50 may include an electriccylinder used to extend and retract beam 52 from support rail 150.Cylinder 102 extends parallel to beam 52 and may be supported on supportrail 150, as shown. It will be appreciated that cylinder 102 may besupported on the frame of enclosure 10 or another structure as well. Inthe depicted example, a mounting plate 210 is attached to the supportrail, as by welds. The mounting plate 210 is provided with a number ofmounting holes 212 on either side to allow attachment of a cylinderbracket 214. As shown, holes 212 may be provided on both sides ofmounting plate 210 to allow attachment of cylinder 102 on either side ofsupport rail 150 depending on the location of the slide out 20. Theprovision of multiple mounting holes also provides flexibility forpositioning the cylinder 102.

Cylinder bracket 214 may have any configuration suited for a givencylinder 102. In the example shown, cylinder bracket 214 is generally anL-shaped member with a lower leg 216 attaching to the mounting plate 210and a pair of upstanding legs 218 that extend upward adjacent to supportrail 150. In the example shown, cylinder 102 is supported between theupstanding legs 218 and secured by a suitable fastener 220. A motor 222is coupled to electronic cylinder 102 and may be supported on an endplate 224 extending from one end of cylinder 102. Motor 222 may includean internal controller 225 that controls operation of motor 222. Inaddition, for remote operation, motor 222 may include an antenna 226.The user may operate motor 222, through a switch located withinenclosure 10, or elsewhere, to selectively extend and retract slide out20. For example, motor 222 is operated in one rotational direction toextend telescoping rod 104 at one end of cylinder 102 to extend slideout 20, and rotated in the opposite direction to retract telescoping rod104 and, thereby, slide out 20.

FIG. 9 illustrates another view of beam 52 and support rail 150 andprovides additional detail with respect to the above-noted aspects.FIGS. 10A, 10B, and 10C illustrate alternative embodiments of an arcuatesupport rail 150. In FIG. 10A, support rail 150 is shown in asymmetrical curve, with the inner edge of each end 254/256 a horizontaldistance of Q/2 from vertex 252 (the lengthwise/horizontal center ofsupport rail 150). FIG. 10B shows an alternative arrangement wheresupport beam 150 curves more sharply at end 254, thereby positioningvertex 252 closer to the same, and curves more gently toward end 256.FIG. 10C illustrates yet another alternative embodiment where supportbeam 150 curves more sharply at end 256, thereby positioning vertex 252closer to the same, and curves more gently toward end 254. It will beappreciated that the curvature need not be constant at any given pointon support rail 150, and may be larger or smaller in magnitude thanthose depicted.

As is visible in FIGS. 10A, 10B, 10C, and other drawings herein, firstand second ends 254 and 256 are level with each other, or otherwisearranged at the same relative position with respect to the height andlength of enclosure 10. Therefore, regardless of the curvature ofarcuate support rail 150, the magnitude of incline leading to vertex 252from the mounting point within or on enclosure 10 at which end 256attaches is equal to magnitude of decline from vertex 252 to end 254.

While the curvature in FIGS. 10A, 10B, and 10C may be exaggerated, allcurvatures and lengths are embraced according to the disclosures herein.The terminal ends and/or coupling components of support rail(s) 150illustrated in FIGS. 10A, 10B, and 10C may be excluded for purposes ofthis illustration.

While support rail 150, beam 52, and other elements may be described aschannels or according to specific geometries, it is understoodalternatives not expressly illustrated are embraced herein. For example,support rail 150 can be any structure capable of constraining or guidingbeam guide 258 in one or more dimensions as it displaces while connectedto beam 52.

FIG. 11 illustrates an alternative partial view of enclosure 10,particularly showing the mounting or anchor points for each support beam150. FIG. 11 shows that each support beam 150 is mounted withinenclosure 10 at the same relative height H from level ground or anyother reference (e.g., the plane represented by the dashed line 282). Inthis way, each support beam 150 is “level” with the others, notnecessarily at all times with respect to, e.g., gravity, but at alltimes aligned with others with respect to the geometry of enclosure 10.

In some embodiments, the drive assembly 50 is configured to maintainengagement between the beam 52 and the drive gear assembly 70. Forexample, the drive assembly 50 may be configured such that the supportrail 150 presses the beam 52 into engagement with the drive gearassembly 70 to ensure that the beam 52 doesn't displace upward withinthe support rail 150 out of engagement with the drive gear assembly 70,and/or the drive assembly 50 may be configured such that the supportrail 150 maintains alignment of the beam 52 within the channel definedby the support rail 150 to ensure that the beam 52 does not slidelaterally within the support rail 150 out of engagement with the drivegear assembly 70. In this manner, engagement between the beam 52 thedrive gear assembly 70 will be maintained. This constant engagement willhelp lock the beam 52 within the support rail 150, inhibit free orunintended extension or retraction of the beam 52 relative to thesupport rail 150, as the actuator 100 will need to be activated toovercome the pressure applied to the beam 52 within the support rail150.

FIGS. 12A-12B illustrate an exemplary drive assembly 50 configured tomaintain engagement and alignment between the beam 52 and the drive gearassembly 70, according to one or more embodiments. In the illustratedexample, a pressure pad 260 is arranged on the support rail 150. Here,the pressure pad 260 extends into the channel defined by the supportrail 150, and the pressure pad 260 engages and applies pressure to a topface of the beam 52 that is opposite to the bottom face of the beam 52on which the first and second rows of teeth 54, 56 are formed. With thisarrangement, the pressure pad 260 urges the first and second rows ofteeth 54, 56 of the beam 52 downward into engagement with the first andsecond gear wheels 71, 72 of the drive gear assembly 70. The pressurepad 260 may also be configured to align (or maintain alignment of) thebeam 52 laterally within the channel of the support rail 150, such thatthe first and second rows of teeth 54, 56 are oriented over the firstand second gear wheels 71, 72. In the illustrated example, the pressurepad 260 is configured as a “C” shaped bracket such that, in addition toactively pressing the beam 52 onto the drive gear assembly 70, the beam52 rides within the recess defined by the “C” shape of the pressure pad260, such that the pressure pad 260 defines a path through which thebeam 52 may travel as it travels within the support rail 150. Here, forexample, the pressure pad 260 centers the beam 52 within the supportrail 150 so that the first and second rows of teeth 54, 56 are orientedover the first and second gear wheels 71, 72, thereby inhibiting atleast some lateral displacement of the beam 52 within the support rail150 that may otherwise result in the first and second rows of teeth 54,56 moving laterally relative to the drive gear assembly 70 into aposition where they may not engage the first and second gear wheels 71,72. Thus, in some examples, the pressure pad 260 may include a pair offlanges 262,264 that define a path within which the beam 52 travels,thereby aligning (or centering) the beam 52 within the support rail 150.The pressure pad 260 may be formed of various materials, includingelastomeric materials, polymer materials, metallic materials, etc. Insome examples, the pressure pad 260 is formed of a self-lubricatingmaterial; however, the pressure pad 260 may be lubricated from anexternal source regardless of the material from which it is formed.Also, as illustrated in FIG. 12A, a cover 270 may be provided over thedrive gear assembly 70 to protect users from moving parts.

While the claimed subject matter of the present application has beendescribed with reference to certain embodiments, it will be understoodby those skilled in the art that various changes may be made andequivalents may be substituted without departing from the scope orspirit of the claimed subject matter. In addition, many modificationsmay be made to adapt a particular situation or material to the teachingsof the claimed subject matter without departing from its scope.Therefore, it is intended that the claimed subject matter not be limitedto the particular embodiments disclosed, but that the claimed subjectmatter will include all embodiments falling within the scope of theappended claims.

1. A drive assembly for reciprocating a slide out disposed in an openingof an enclosure between an extended position and a retracted position,the drive assembly comprising: a support rail defining a channel, thesupport rail being arcuately shaped; a beam having a front portion thatis attachable to the slide out and having a guide portion opposite fromthe front portion that is at least partially enclosed within thechannel; and an actuator coupled to the beam to selectively extend andretract the beam relative to the support rail, wherein a curvature ofthe support rail varies orientation of the slide out relative to theopening based on the position of the guide portion within the channel.2. The drive assembly of claim 1, wherein, as the beam is extendedthrough the support rail, the curvature of the support rail angles thebeam downwards such that the guide portion of the beam is orientedhigher than the front portion of the beam.
 3. The drive assembly ofclaim 1, wherein, as the beam is retracted through the support rail, thecurvature of the support rail angles the beam upwards such that theguide portion of the beam is oriented lower than the front portion ofthe beam.
 4. The drive assembly of claim 1, wherein the support railincludes a symmetrical or asymmetrical arcuate shape.
 5. The driveassembly of claim 1, further comprising a drive gear engageable with theat least one row of teeth provided on the beam.
 6. The drive assembly ofclaim 5, wherein the support rail is configured to press the beam intoengagement with the drive gear.
 7. The drive assembly of claim 5,wherein the at least one row of teeth provided on the beam includes afirst row of teeth and a second row of teeth, and wherein the drive gearincludes a first gear wheel engageable with the first row of teeth and asecond gear wheel engageable with the second row of teeth.
 8. The driveassembly of claim 7, wherein teeth in the first row of teeth are offsetrelative to teeth in the second row of teeth, and wherein the first gearwheel is rotationally offset relative to the second gear wheel.
 9. Thedrive assembly of claim 7, wherein the support rail is configured tomaintain engagement of the first and second row of teeth on the beam onthe first and second gear wheels of the drive gear.
 10. The driveassembly of claim 1, wherein the guide portion includes a slide memberconfigured to slide within the channel.
 11. The drive assembly of claim10, wherein the slide member is configured to rotate relative to thebeam.
 12. The drive assembly of claim 1, wherein the actuator isselected from the group consisting of an electric cylinder, a hydraulicactuator, and a pneumatic actuator.
 13. The drive assembly of claim 1,further comprising a drive gear connected to the support rail, the drivegear having a first and second gear wheel that are engageable with afirst and second row of teeth provided on the beam, wherein the firstand second gear wheels are mounted on a common hub.
 14. The driveassembly of claim 13, wherein the drive gear further comprises a supportwheel mounted on the common hub, the support wheel being configured torotate independently of the common hub and engaging the beam between thefirst row of teeth and the second row of teeth.
 15. The drive assemblyof claim 13, further comprising; a stub shaft axially extending from andrigidly attached to the common hub, wherein rotation of the stub shaftimparts rotation on the first gear wheel and the second gear wheel tothereby drive the beam; and a cross member that couples the stub shaftto a second drive assembly, the cross member synchronizing the driveassembly and the second drive assembly.
 16. An expandable enclosurecomprising: an enclosure having an opening; a slide out provided in theopening of the enclosure and extendable from the enclosure; and a driveassembly for extending and retracting the slide out, the drive assemblycomprising: a support rail defining a channel, the support rail beingarcuately shaped; a beam having a front portion that is attachable tothe slide out and having a guide portion opposite from the front portionthat is at least partially enclosed within the channel; and an actuatorcoupled to the beam to selectively extend and retract the beam relativeto the support rail, wherein a curvature of the support rail variesorientation of the slide out relative to the opening based on theposition of the guide portion within the channel.
 17. The expandableenclosure of claim 16, wherein the enclosure is a self-powered ortowable vehicle.
 18. The expandable enclosure of claim 16, wherein theactuator is selected from the group consisting of an electric cylinder,a hydraulic actuator, and a pneumatic actuator.
 19. The expandableenclosure of claim 16, further comprising a drive gear connected to thesupport rail, wherein the drive gear comprises: a hub; a first andsecond gear wheel arranged on the hub and respectively engaging a firstand second row of teeth provided on the beam; a support wheel arrangedon the hub and engaging the beam between the first row of teeth and thesecond row of teeth, the support wheel being configured to rotateindependently of the hub; and a stub shaft axially extending from andrigidly attached to the hub, wherein rotation of the stub shaft impartsrotation on the first gear wheel and the second gear wheel to therebydrive the beam.
 20. The expandable enclosure of claim 19, furthercomprising a cross member that couples the stub shaft to a second driveassembly, the cross member synchronizing the drive assembly and thesecond drive assembly.